Remedy for dry eye syndrome

ABSTRACT

A treatment for dry eye syndrome. An at least partially sealed chamber including a reservoir for moisture for surrounding the eyes is disclosed. The invention may be transparent for use during the day or in association with prescription or non-prescription lenses. The moisture chamber may also be opaque to act as a blackout mask for sleeping.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/645,718 filed Aug. 21, 2003 now abandoned which is a continuation ofapplication Ser. No. 10/123,604 (now U.S. Pat. No. 6,641,264 B1)entitled “Remedy For Dry Eye Syndrome” and filed Apr. 15, 2002.

FIELD OF THE INVENTION

The present invention relates to the treatment of dry eye syndrome. Moreparticularly, it relates to altering the local environment to reduce thediscomfort of dry eye syndrome.

BACKGROUND OF THE INVENTION

Dry eye syndrome is one of the most commonly treated eye problems in theUnited States. Dry eye syndrome is also known as keratitis sicca,keratoconjunctivitis sicca (KCS) xerophthalmia, and lacrimalinsufficiency. It is estimated that over ten million Americans and 30million persons worldwide suffer from dry eye syndrome.

For a large fraction of dry eye patients, dry eye syndrome createsdiscomfort or annoyance. For those severely afflicted, dry eye syndromecan be debilitating and, in some circumstances, even sight-threatening.In extremely severe cases, dry eye syndrome can even lead to the loss ofan eye.

Dry eye syndrome typically results from deficiency in the quality orquantity of tears produced by the patient. Precorneal tear film hastraditionally been considered to have a three-layered structure. Theclosest to the cornea lies the mucin, or mucus, layer. The mucin layerprovides an interface between the corneal epithelium and the remainderof the tear film. Overlying the mucin layer is the watery aqueous layer,which is the thickest layer of the three. The outermost layer of theprecorneal tear film is the lipid layer. The lipid layer is an oily filmthat reduces evaporation from the aqueous layer beneath it.

The middle aqueous layer provides moisture to the corneal tissue,carries important nutrients, and serves to remove metabolic wasteproduced by the cornea. Deficiency in any of the three layers of theprecorneal tear film can result in complaints of dry, gritty feeling orburning eyes.

The mucin that forms the mucin layer, nearest the cornea, is secreted bygoblet cells in the conjunctiva. The conjunctiva is the transparenttissue that covers the sclera and the backside of the eyelids. The mucinlayer functions to decrease surface tension of the tear film. Inaddition, the cornea itself is hydrophobic. Without the mucin layer toprovide a bridge between the cornea and the aqueous layer, the aqueouslayer would bead up and allow dry spot formation on the cornea.

The aqueous layer is secreted primarily by the glands of Wolfring andKrause located in the eyelid margin. The aqueous layer helps provide anoptically smooth, transparent surface to the precorneal tear film. Thelipid layer is secreted by the meibomian glands, and the glands of Zeissand Moll. The glands of Zeiss and Moll are also located at the eyelidmargin.

Blinking is essential to maintenance of the precorneal tear film. Duringeach blink, the eyelid wipes over the surface of the cornea, smoothingthe mucin layer and spreading the overlying aqueous and lipid layers toprovide a completely wetted surface. In between blinks, the tear filmthins due to evaporation of the aqueous layer. If evaporation isexcessive, dry spots may form on the surface of the cornea.

Deficiency, or imperfect quality, of any of the three component layerscan lead to dry eye symptoms. Many systemic and external factors cancontribute to dry eye syndrome. For example, Sjogren's syndrome isassociated with arthritic diseases in combination with dry eye and drymouth. Deficiency of Vitamin A, use of oral contraceptives andenvironmental factors can all contribute to dry eye syndrome.

Recent research into the natural history of dry eye syndrome has shownthat the disease progresses through four stages. Each stage is aconsequence of the preceding stage. The stages are:

-   -   1. Loss of water from the aqueous layer of the tear film leading        to an increase in the tear film osmolarity;    -   2. Loss of conjunctival goblet cells and decreased corneal        glycogen;    -   3. Increased loss of corneal squamous epithelial cells;    -   4. Destabilization of the interface between the corneal surface        and the tear film.

Either decreased secretion of tear film components or increasedevaporation lead to increased tear film osmolarity and the followingstages that lead to eventual corneal decompensation and the seriousconsequences of dry eye syndrome.

The adnexa of the eye may also be involved in dry eye syndrome. Theadnexa of the eye include the structures surrounding the eye such as theeyelids, eye lashes, the tear drainage and tear production structures.Blepharitis commonly contributes to dry eye syndrome. Blepharitistypically results from bacterial infection of the tiny glands in themargin of the eyelid. These glands include the glands of Zeiss, Moll andWolfring as well as the meibomian glands. Most commonly, the affectedglands are the meibomian glands. In bacterial blepharitis, bacterialinfection causes the meibomian glands to become plugged, and thus not beable to produce a normal lipid layer to contribute to the tear film.Some bacteria that infect the glands also secrete exotoxins that seepout of the glands into the eye and injure the corneal epithelium.

Treatments of dry eye syndrome vary depending upon the type ofpresentation. The most common treatment for dry eye syndrome is the useof artificial tear supplements to provide additional moisture andlubrication to the corneal surface. Artificial tear eye drops are placedon the eye by the patient. Artificial tear supplements must be usedregularly and often to be effective.

Lubricant ointments may also be employed. Ointments are usually used atbedtime because they tend to be messy and blur vision. For somepatients, even the use of ointments is not sufficient to provide comfortduring sleep.

Tears drain from the eye through the lacrimal drainage system. Tinyopenings at the nasal corner of each upper and lower eyelid are calledthe lacrimal puncta. The lacrimal puncta lead into ducts that drain intothe nasopharynx.

One treatment for dry eye syndrome is to partially or completely closeone or more lacrimal puncta to reduce tear outflow into the lacrimaldrainage apparatus. Traditionally, this closure was accomplishedsurgically or by cautery. In the last decade, however, temporary andpermanent punctal occlusion plugs have been utilized.

Permanent punctal plugs are typically made from surgical silicone;temporary plugs are generally made of soluble collagen. Collagen plugsdissolve over a period of days and are helpful in diagnosis.

Punctal plugs are placed into the lacrimal puncta, or lacrimal drainageducts. The plugs impede the outflow of tears from the eye. This approachslows the outflow of tears and retains them in the eyes longer, oftenrelieving symptoms. Punctal plugs have the distinct advantage of beingreadily removable and avoid the issues of scar formation.

Blepharitis is sometimes treated by the use of antibiotic medications.Another important treatment for blepharitis is the application of warmsoaks and lid scrubs. In this form of treatment, the patient applies awarm wet washcloth to the eyelids for a period of time to providehumidity, warmth and to help soften blockage of and restore flow fromthe meibomian glands. Lid scrubs are practiced by taking a mild,nonirritating soap and vigorously scrubbing the eyelid margins with theyeyes closed, so as to massage the meibomian glands and increaseproduction. The surfactant helps to dissolve the greasy blockage of themeibomian glands.

Patients who have severe dry eye syndrome often suffer disrupted sleepbecause they cannot go for longer than an hour or so without applyingtear supplements to the eyes. This can lead to pronounced sleepdeprivation and a consequent reduction in quality of life.

A variety of researchers have been seeking other medicinal treatmentsfor dry eye syndrome. Largely, this research is directed atpharmaceutical efforts to increase tear production.

Despite the many treatment options available, there remains no cure fordry eye syndrome. A great many patients still have substantial and evendebilitating discomfort because of dry eye syndrome. Very few treatmentoptions exist to provide comfort for dry eye syndrome patients duringsleep.

SUMMARY OF THE INVENTION

The invention generally includes an at least partially enclosed chamberat least partially sealed around the eyes and a reservoir for water oranother liquid subject to evaporation to provide a high humidityenvironment in the vicinity of the eyes. The invention may incorporate ablackout mask for use while sleeping or may incorporate a transparentfront structure to accommodate nonprescription or prescription lenses.Another embodiment of the invention may be incorporated into a hat witha brim.

The invention benefits the patient by increasing comfort andameliorating the damaging effect of dry eye syndrome on the patient 'seyes. The invention also improves the ability to of the patient toachieve a normal sleep cycle of 6 to 10 hours.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear plan view of a first embodiment of a pre-cornealhumidity chamber in accordance with the present invention;

FIG. 2 is a sectional view of the pre-corneal humidity chamber of FIG.1;

FIG. 3 is a rear plan view of a second embodiment of the pre-cornealhumidity chamber;

FIG. 4 is an elevational and sectional view of the pre-corneal humiditychamber of FIG. 3;

FIG. 5 is an elevational view of a third embodiment of the pre-cornealhumidity chamber; and

FIG. 6 is a perspective view of the pre-corneal humidity chamberdepicted in FIG. 5 with a reservoir shown in phantom.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a first embodiment of a pre-corneal humiditychamber 10 is depicted. This embodiment generally includes a sleep mask12, moisture reservoir 14, seal 16 and retaining member 18.

Sleep mask 12 is preferably made of a moisture impermeable and flexiblematerial. Sleep mask 12 is shaped and sized appropriately to conform tothe area surrounding the eyes and orbit in a comfortable fashion. Sleepmask 12 is preferably shaped so that the perimeter 20 thereof fitssnuggly against the skin of the face.

Moisture reservoir 14 may include any type of device adapted to containand release a material subject to evaporation or sublimation. Examplesinclude an absorbent fibrous substance, a chamber for holding a materialsubject to vaporization and a chemical mixture that releases as a vapordesired substance.

Seal 16 generally conforms to perimeter 20 of sleep mask 12. Sleep mask12 may also be configured without seal 16 so long as sleep mask 16 isgenerally closely fitting to the area surrounding the eyes. Seal 16 ispreferably made from a soft, conforming, hypoallergenic material. Thecross-section of seal 16 is preferably rounded as depicted in FIG. 2 soas to provide a comfortable junction between seal 16 and the skin of theuser. Seal 16 may be made from such materials as closed or open cellfoam, silicon or moisture impermeable fabric.

Retaining member 18 preferably comprises an elastic strap as depicted inFIGS. 1 and 2. Retaining member 18 may however, be constructed ofelastic straps, Velcro, temples as used on eyeglasses or any otherstructure that would appropriately retain sleep mask 12 in a comfortableposition in apposition to the face of the user.

Moisture reservoir 14 is preferably made from an absorbent material,which readily allows for evaporation of water or other evaporativeliquids. A sublimating solid may be employed as well. Moisture reservoir14 may include two layers, an inner layer 24 and a moisture layer 26.Inner layer 24 is preferably a lint free material with antibacterial,antifungal and wicking properties. Moisture layer 26 is preferably madeup of an absorbent material. The absorbent material may include superabsorbent particles or a jellified water product. Moisture reservoir 14is preferably removably attachable to sleep mask 12. Attachment betweenmoisture reservoir 14 and sleep mask 12 may be achieved by pressuresensitive adhesive backing, Velcro or any other attachment mechanismknown to the removable attachment arts.

Moisture reservoir 14 may be provided in the dry state and moistened atthe time of desired use. Moisture reservoir 14 may also be providedpre-moistened in a sealed container. Moisture reservoir 14 may bemoistened with, for example, purified water, Ringer's solution, or abuffered purified formulation of an appropriate ionic and electrolyticcomposition to mimic human tears.

Referring to FIGS. 3 and 4, another embodiment of the invention isdepicted. This embodiment of the pre-corneal humidity chamber 10generally includes a frame front 28 and temples 30. Frame front 28 andtemples 30 may be structured in a fashion generally similar toconventional eyeglasses or in a fashion generally similar to a goggle.This description will be most appropriate for an embodiment of thepre-corneal humidity chamber 10 structured similarly to a conventionalpair of eyeglasses, however, this should not be considered limiting. Oneskilled in the art will readily realize that the general principal canbe adapted to any sort of eyewear construction.

Frame front 28 generally includes eye wire 32, bridge 34, end piece 36and seal 38. Each eye wire 32 encloses and supports lens 40. Lens 40 maybe a prescription or nonprescription lens. Lens 40 may also be acolorless transparent lens or a tinted lens. Frame front 28 isconstructed to conform generally to the contours of the user's face.Seal 38 preferably runs around the perimeter 42 of frame front 28.

Seal 38 can be constructed of any soft pliable, moisture impermeablematerial and serves to seal the juncture between frame front 28 and theface of the user. Referring particularly to FIG. 4, temples 30 generallyinclude hinge 44, moisture reservoir 46, earpiece 48, and a portion ofseal 38. Seal 38 preferably continues from frame front 28 to enclosemoisture reservoir 46 within the same space that the user's eyes areenclosed in. Temples 30 are mirror images of one another and join framefront 28 at hinge 44. Hinge 44 is made of two halves one connected toend piece 36 and one connected to temple 30. Moisture reservoir 46 issimilar in structure to moisture reservoir 14 of the previousembodiment. Moisture reservoir 46 conveniently may be attached totemples 30 but may be incorporated into any part of the precornealhumidity chamber 10 that allows evaporation in to the enclosureincluding the eyes.

It will be apparent to one skilled in the art that the embodimentdepicted in FIGS. 3 and 4 can readily be modified to treat only one eyeas can the embodiment depicted in FIGS. 1 and 2.

Referring to FIGS. 5 and 6, another embodiment of pre-corneal humiditychamber 10 is depicted. This embodiment of the invention generallyincludes hat 50, brim 52, transparent enclosure 54 and moisturereservoir 56.

Hat 50 is preferably a baseball style cap but may include any hat orvisor having a brim. Brim 52 may be of any shape or size so long as itprotrudes forward of the brow on the front of the hat 50.

Transparent enclosure 54 is preferably an optically clear material.Transparent enclosure 54 extends downward from brim 52 and is configuredto fit closely to the face and temples of the user. Transparentenclosure 54 is preferably made from an optically clear transparentmaterial such as polycarbonate or acrylic.

Moisture reservoir 56 is preferably secured to the under side 58 of brim52. Moisture reservoir 56 may also be incorporated anywhere withintransparent enclosure 54. Moisture reservoir 56 may also be secured totransparent enclosure 54. In addition, moisture reservoir 56 may be anintegral part of brim 52 or hat 50.

Moisture reservoir 56 may be constructed of a fibrous absorbent polymer,which absorbs water. Moisture reservoir 56 may also be made up of superabsorbent particles or a jellified water product as indicated in theembodiments above.

In operation, the pre-corneal humidity chamber 10 is worn by the user soas to enclose the user's eyes. Prior to wearing, the user applies amoisturizing compound such as water, Ringer's solution or an artificialtear solution to moisture reservoir 14, moisture reservoir 46 ormoisture reservoir 56. Any of moisture reservoirs 14, 46 or 56 may besupplied in a dry state and moistened at the time of use or may besupplied in a pre-moistened state sealed in a package and applied at thetime of desired use.

Referring to FIGS. 1 and 2, sleep mask 12 is applied over the eyes priorto going to sleep. The evaporation of moisture from moisture reservoir14 provides a high humidity ambient environment around the eyes, thus,reducing evaporation of the watery portion of the tears, thus enhancingthe ability of the patient's tears to provide a comfortable environmentfor the eyes.

In addition, sleep mask 12 may be provided with a moisture reservoir 14capable of holding a large volume of liquid in order to provide along-term warm moist soak for the eyes. This approach may be used as anadjunct to the treatment of blepharitis. Referring to FIGS. 3 and 4,this embodiment of the pre-corneal humidity chamber 10 is worn in afashion similar to eyeglasses or conventional goggles. Prior to wearing,moisture reservoir 46 is replaced if pre-moistened or moistened.Moisture reservoir 46 then evaporates moisture to provide a highhumidity environment for the eyes within the pre-corneal humiditychamber 10. In addition, the pre-corneal humidity chamber 10 of thisembodiment provides protection of evaporation caused by air movement. Inaddition, pre-corneal humidity chamber 10 of this embodiment tends toexclude atmospheric irritants and other air quality irritants that mayirritate the eye.

Referring to FIGS. 5 and 6, prior to wearing this embodiment of thepre-corneal humidity chamber 10, moisture reservoir 56 is moistened orinserted if pre-moistened. This embodiment of the pre-corneal humiditychamber 10 also tends to protect from increased evaporation due to airmovement as well as tending to exclude irritants in the ambient air.

In testing an exemplary reservoir was placed in a sealed plastic bag.The humidity within the bag rose to in excess of 90% and remained atthat level for over eight hours. This is long enough to provide comfortduring a normal sleep cycle. A test subject reported dramaticallyimproved comfort during sleep using an embodiment of the invention.

The present invention may be embodied in other specific forms withoutdeparting from the spirit of any of the essential attributes thereof;therefore, the illustrated embodiments should be considered in allrespects as illustrative and not restrictive, reference being made tothe appended claims rather than to the foregoing description to indicatethe scope of the invention.

1. A device to improve the comfort and ocular health of a dry eyesyndrome subject and to reduce the harmful effect of dry eye syndrome onthe eye and adnexa, the device comprising: a flexible eye cover having aperimeter; a soft, conforming member generally conforming to theperimeter of the eye cover so as to create a partial enclosure inoperable cooperation with the eye cover; an absorbent moisture padformed of an absorbent substance and capable of evaporatively releasingan absorbed substance, the absorbent moisture pad being removeablyinsertable into the partial enclosure formed by the member and theflexible eye cover; and an elastic retaining member operably connectableto the flexible eye cover.
 2. The device as claimed in claim 1, in whichthe retaining member is sized so as to be applyable about the head ofthe dry eye subject.
 3. The device as claimed in claim 1, in which theabsorbent moisture pad comprises a first absorbent layer and a secondlayer.
 4. The device as claimed in claim 1, in which the absorbentmoisture pad is supplied dry and moistened at the time of desired use.5. The device as claimed in claim 1, in which the absorbent moisture padis moistened with a liquid selected from a group consisting of water,purified water, Ringer's solution and a buffered formulation of anappropriate ionic and electrolytic composition to mimic human tears. 6.The device as claimed in claim 1, in which the flexible eye cover issubstantially sealed to the face of the dry eye syndrome subject.
 7. Thedevice as claimed in claim 1, in which the flexible eye cover comprisesan opaque light blocking material.
 8. A method for ameliorating theeffects of dry eye syndrome an eye, the method comprising the steps of:substantially covering the eye with a flexible eye cover adapted to fitclosely to the eye and adnexa thereby creating a local atmosphericmicroenvironment in the vicinity surrounding the eye, the flexible coverhaving a perimeter; interposing a soft, conforming member generallyconforming to the perimeter of the eye cover between the eye coverperimeter and the subject; removably inserting an absorbent moisture padformed of an absorbent substance and capable of evaporatively releasingan absorbed substance between the eye cover and the eye; and securingthe eye cover to the subject's head with an elastic retaining memberoperably connectable to the flexible eye cover.
 9. The method as claimedin claim 8, further comprising the step of moistening the moisture padwith a material subject to vaporization.
 10. The method as claimed inclaim 8, in which the in which a humidity level achieved beneath the eyecover exceeds 90% relative humidity.
 11. The method as claimed in claim8, in which a humidity level achieved beneath the eye cover exceeds 90%relative humidity and is maintained for in excess of 6 hours.